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Effects of Positively Charged Dicyandiamide and Nitrogen Fertilizer Sources on Nitrous Oxide Emissions in Irrigated Corn
Author(s) -
Waterhouse Hannah,
Wade Jordon,
Horwath William R.,
Burger Martin
Publication year - 2017
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2017.01.0033
Subject(s) - nitrification , chemistry , fertilizer , nitrous oxide , loam , nitrate , agronomy , ammonium , urea , urease , calcium nitrate , nitrogen , ammonia , ammonium nitrate , zoology , soil water , calcium , environmental science , biochemistry , organic chemistry , biology , soil science
Synthetic nitrogen (N) fertilizer formulations vary in their effects as substrates on nitrous oxide (N 2 O) emissions. Mitigation of N 2 O emissions can potentially be achieved through appropriate choice of N fertilizer sources combined with stabilizers. The effects of three N fertilizers and urease and nitrification inhibitors on N 2 O emissions, crop N uptake, and yields were determined in a furrow‐irrigated corn ( Zea mays L.) system in Reiff loam soil in the Sacramento Valley of California for one growing season. Aqua ammonia (Aq. NH 3 ), urea ammonium nitrate (UAN), and calcium nitrate were sidedressed at the rate of 202 kg N ha −1 . The control treatment received only starter fertilizer (20 kg N ha −1 ). Total seasonal emissions were in the order Aq. NH 3 > UAN > calcium nitrate = control with 1.38, 0.97, 0.35, and 0.27 kg N 2 O‐N ha −1 , respectively. A novel, positively charged form of dicyandiamide, KAS‐771G77 (G77), was combined with Aq. NH 3 and UAN to test the effectiveness of this nitrification inhibitor in reducing N 2 O emissions. When combined with Aq. NH 3 , G77 did not reduce the emissions, but G77 significantly lowered them in the UAN treatment. A similar reduction of N 2 O emissions in the UAN treatment was achieved with the urease and nitrification inhibitor AgrotainPlus. Yields and N use efficiency did not differ among the fertilized treatments. Ammoniacal fertilizers had higher N 2 O emissions than nitrate‐based fertilizers, which could imply nitrification pathways as a source of N 2 O emissions. The use of G77 or AgrotainPlus, when applied with UAN, was an effective N 2 O mitigation practice. Core Ideas Pure ammonia fertilizer produced the highest N 2 O emissions. N 2 O emissions were similar in control and calcium nitrate treatment. Positively charged DCD reduced N 2 O emissions with UAN, but not with Aq. NH 3 . Positively charged DCD with UAN was as effective as AgrotainPlus in lowering N 2 O.